Engine starter control system

ABSTRACT

An electrical starting system for an internal combustion engine feeds electric power from the ignition switch to the engine starter motor solenoid. When the ignition switch is switched from the ignition position to the ignition-start position and if the engine does not start, the starter motor can not be energized again until the ignition switch is returned to the &#39;&#39;&#39;&#39;off&#39;&#39;&#39;&#39; position. If the engine starts the starter is automatically disconnected. The system includes two separate pairs of ganged switches, each pair of responsive to a different control such that one switch in each pair upon switching from one state to another holds its associated control to maintain that state and a change of state of each control is initiated by one of the switches associated with the other control.

United States Patent 1191 Swartz May 27, 1975 [54] ENGINE STARTERCONTROL SYSTEM 3,681,658 8/1972 Naoi et a1. 290/37 AX [76] Inventor: gigi gg ah g $2 Primary Examiner-Charles J. Myhre Assistant ExaminerW.Rutledge, Jr. [22] Filed: Apr. 27, 1973 Attorney, Agent, or Firm-RobertT. Dunn [21] Appl. No.: 354,990 [57] ABSTRACT An electrical startingsystem for an internal combus- Cl --123/179 290/37; 290/38 tion enginefeeds electric power from the ignition [5 Clwitch to the engine tartermotor oenoid when new of Search l23/179 B, 179 198 D, ignition switch isswitched from the ignition position 123/198 290/37 R, 38 to theignition-start position and if the engine does not start, the startermotor can not be energized again References Clted until the ignitionswitch is returned to the off" posi- UNITED STATES PATENTS tion. If theengine starts the starter is automatically 3,264,483 8/1966 Alexander,290/38 R disconnected- The System includes two Separate Pairs 3,443,1125/1969 Hun-tzinger... 290/38 R of g g h s, each p r f sp nsive to adiffer- 3,573,480 6/1971 Cummins 290/38 ent control such that one switchin each pair upon 3,573,481 1971 Cummins 290/37 X switching from onestate to another holds its associ- 3,577,00l 4/1971 Cummins 290/37 Xatgd control to maintain that tate and a change of 3,573,981 5/ 1971 P Pet 290/38 R state of each control is initiated by one of the switches3,593,697 I 7/1971 ClOlll 290/37 x associated with the other cohhoh3,628,041 12/1971 Cummms 290/37 7 0 3,629,598 12/1971 Rachel 290/38 R 13Claims, 6 Drawing Figures I FIRST SECOND cf CONTROL 4 CONTROL DEVICEDEVICE 1 23 26 C 1 SWITCH h SWITCH A 2 22 32 2s 33 SWITCH SWITCH I QSHEET 1 ENGINE IGNITION SYSTEM 1 ENGINE QFFQ I IGNITION v E 8 C STARTERSWITCH IGNITIONO 0 CONTROL 9 SYSTEM IGNITION-START V- R ENGINE GEN.VOLTAGE REGULATOR E G E I /4 sTART ER MoToR ENG'NE STARTER MOTOR BATTERY2 SOLENOID SWITCH I FIRST SECOND c CONTROL CONTROL DEVICE DEVICE 11 2326 2| v r. 111 SWITCH SWITCH SWITCH SWITCH PATENTED MAY 2 71975 SHEETPAIENI uAYzlivs SHEET w o i FIG. 6

ENGINE STARTER CONTROL SYSTEM BACKGROUND OF THE INVENTION This inventionrelates to control systems for internal combustion engine starter motorsand more particularly, to a circuit between the ignition switch andstarter motor solenoid in an automotive vehicle which restricts thesequence for starting the engine to protect the starter motor and theengine.

The electric starting system for an internal combustion engine typicallyincludes a battery which provides DC electric power, a starter motorwhich mechanically engages a flywheel on the engine, a starter motorsolenoid which feeds DC electric power from the battery to the motor,and an ignition switch which connects battery power to the ignitionsystem and connects battery power to the starter solenoid to energizethe starter motor. The usual sequence to start such a motor begins withthe ignition switch at the off position at which no battery power isconnected to the engine ignition system or to the 'starter solenoid. Theoperator first switches the ignition switch from the off position to theignition position at which battery power is connected to the engineignition system. Then the operator turns the ignition switch, usually inthe same direction, to the ignition-start position and holds theignition switch in that position until the engine starts. At theignitionstart position of the ignition switch, battery power is stillconnected to the engine ignition system and in addition, the startersolenoid is energized feeding battery power to the starter motor whichimmediately drives the engine flywheel. As soon as the engine starts,the operator is supposed to release the ignition switch from theignition-start position so that the switch returns to the ignitionposition, which is the normal running position of this switch.

If the operator holds the ignition switch in the ignition-start positionafter the engine has started and while the starter motor is stillengaging the engine flywheel, the engine will then drive the startermotor, overspeeding the starter motor. This may damage or causeexcessive wear of the starter motor.

If the starter motor is energized while the engine is turning, themechanical engagement of the starter motor with the engine flywheel maybe severely damaged. This could occur if the operator shouldinadvertently turn the ignition switch from ignition to ignition startwhile the engine is running. It also occurs if after attempting to startthe motor the operator immediately makes a second attempt to start themotor while the starter motor is still rotating from the previousattempt to start.

Heretofore some efforts have been to provide a system which wouldprevent energizing the starter motor while the engine was running at aspeed greater than cranking speed. Some of these have included afeedback of engine parameters such as oil pressure or engine generatoroutput to operate a switch controlling the start motor solenoid switch.However, generally,

' these prior systems did not attempt to solve the problems which arisefrom the operators immediate atconjunction with a typical electricstarting system for internal combustion engines such as commonly foundin most automotive vehicles. The basic system in these vehicles includesa battery, a starter motor and starter motor solenoid switch, anignition switch and a voltage regulator. The starter control system ofthe present invention is electrically between the ignition switch andthe starter motor solenoid switch so that the starter motor solenoid andhence the starter motor itself can not be energized except through thestarter motor control of the present invention. All other systems of theengine operate independently of the starter motor control system.

In one embodiment of the invention two pairs of switches are providedeach pair being slaved to a different control device. Initially when theignition switch is at the off position, all of the switches are in theirzero state and the controls are also in the zero state. When theignition switch is turned from the off to the ignition position, theengine ignition system of course, is immediately energized directly fromthe ignition switch, but no change of state occurs with regard to any ofthe parts in the starter control system. Thereafter, when the ignitionswitch is switched from the ignition to the ignition-start position,electric power is fed to the starter motor solenoid switch via theignition switch and one of the switches in the starter control system.Also, within the starter control system, one of the controls changesstate and the switches associated therewith also change state causingthe other control to also change state and its associated switches tochange state. Thereafter, if the engine starts, and the ignition switchis properly returned to-the ignition position, one of the controlsremains in the one state and the other is switched back to the zerostate. The starter control system remains in this condition while theengine is running.

Should the operator inadvertently turn the ignition switch to theignition-start position while the engine is running, nothing willhappen, because the starter motor can not be energized via the startercontrol system while it is in the condition described. The starter motorcan only be energized again by returning the ignition switch to the offposition, whereupon all controls and switches in the starter controlsystem return to the zero state, and then commencing the start sequenceagain.

In one embodiment of the present invention, one or more of the switchesin the starter control system are tempt to restart the engine after anunsuccessful attempt to start.

SUMMARY OF THE INVENTION electronic switches such as a siliconcontrolled rectifier (SCR) which of course has two states of operationwhich can be designated the zero state and the one state and has but oneoutput line. Since in all embodiments of the present invention, all theswitches have but one output line, all the switches could be siliconcontrolled rectifiers.

It is preferred in all embodiments of the present invention to provide aresponse to an engine parameter such as oil pressure, generator outputor voltage regulator output to stop electrical power to the startermotor once the engine has started as evidenced by one of theseparameters.

Accordingly, it is an object of the present invention to provide asystem for use in conjunction with the ignition and start system of aconventional automotive engine which prevents reenergization of thestarter motor until the engine ignition switch is placed in the offposition.

It is another object of the present invention to provide a controlsystem for use in conjunction with a conventional automotive enginewhereby damage to the starter motor and damage to the engagementmechanism whereby the starter motor engages the engine which can occuras described above in the Background of the Invention is prevented.

It is another object of the present invention to provide an improvedelectric start system for cranking a typical motor vehicle engine undercontrol of an ignition switch.

It is another object of the present invention to provide in conjunctionwith the ignition system and starter motor system of an internalcombustion engine, means which prevents the operator from energizing thestarter motor until the ignition system for the engine has beende-energized and there energized.

It is a further object of the present invention to provide a system forstarting an internal combustion engine and which prevents energizing theengine starter motor except after first turning off the engine ignition.

The above and other objects and features of the present invention areapparent from the following specific description of embodiments of theinvention which represent the best known uses and applications of theinvention all taken in conjunction with the accompanying drawings andclaims which form a part of this specification.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram illustrating atypical automotive electric starting system incorporating the presentinvention;

FIG. 2 is a block diagram illustrating the principal parts of thestarter control system of the present invention;

FIG. 3 is a schematic diagram illustrating one embodiment of the startercontrol system using two pairs of solenoid controlled switches;

FIG. 4 is a schematic showing a modification of the starter controlsystem embodiment in FIG. 3; and

FIGS. 5 and 6 are schematic diagrams of another embodiment of thestarter control system using an SCR for some of the switching actions inthe system, one schematic showing connections for positive ground andthe other for negative ground.

The block diagram in FIG. 1 shows the essential parts of an electricstarting system for cranking and starting an internal combustion engineincorporating the starter control system of the present invention. Thetotal system includes the ignition switch 1, a battery 2 shown with thepositive terminal grounded, a solenoid switch 3 for feeding power to thestarter motor 4 that cranks the engine, the engine ignition system 5 andthe engine voltage regulator 6. The starter control system 7 which isconstructed as described herein with reference to numerous embodimentsof such a system connects electric power from the ignition switch to thestarter solemold. The five terminals to the starter control system aredesignated I, II, III, IV and V. The terminal II connects to theignition line 8 from the ignition switch and the terminal III connectsto the ignition-start line 9 from the ignition switch. The output of thestarter control system is from terminal IV which feeds line 10 to themotor start solenoid 3. Another input to the starter control system isat terminal V which receives a signal in line 11 from the engine voltageregulator 6. The remaining terminal of the control system, terminal Iconnects to ground.

In operation of the system shown in FIG. 1, the function of the startercontrol system 7 is to feed electric energy via the ignition switch andthe starter control system to the engine start solenoid 3 whenever theignition switch is turned to the ignition-start position which feedsenergy into both lines 8 and 9, provided the ignition start switch isturned to the ignition-start position from the off position. Inaddition, when the ignition switch is in the ignition-start position,the engine start solenoid 3 is energized via the starter control system7 only for so long as there is not sufficient voltage fed to line 11from the voltage regulator 6. For example, when the engine starts andthe voltage regulator produces a sufficient output in line 11,energization of the solenoid 3 via line 10 ceases even thought theproper start sequence has been followed by the operator. A number ofdifferent embodiments of the starter control system 7 are shown in FIGS.2 to 6.

FIG. 2 is a block diagram illustrating the essential features of oneembodiment of the starter control system. This consists of switches Aand B 21 and 22, both controlled by the first control device 23 andswitches A and B 24 and 25, both controlled by the second control device26. Each switch and each control device has a zero and a one state andthe switches are slaved to their associated control device so that whenthe control device is in the zero state the switch is also in the zerostate and when the control device is in the one state the switch is alsoin the one state. The inner connections between the switches and controldevices are as illustrated in FIG. 2. Operation of this system such thatwhen the ignition switch is in the off position (at the I terminal) allthe control devices and switches are in the zero state. In this stateonly switch A 21, is closed.

When the ignition switch is switched to the ignition position, terminalII is energized with battery voltage and so battery voltage is appliedto the inputs of switches 22 and 25. However, these switches are intheir zero state (open) and so nothing happens in the starter controlsystem.

Thereafter, when the ignition switch is switched from the ignitionposition to the ignition-start position, both terminals II and III areenergized with battery power and since switch 21 is closed, batterypower is fed through to line 28, to terminal IV that connects to thestarter motor solenoid which in turn feeds power to the engine startermotor. At the same time, line 28 feeds battery power to the secondcontrol device 26 causing that device to switch from the zero state tothe one state which in turn switches each of the switches 24 and 25 fromthe zero state to the one state, and so these switches are also closed.When switch 24 closes it feeds battery power from terminal III via line27 to terminal IV. Also, when switch 25 closes it feeds battery powerfrom terminal II in line 31 to line 32 that energizes the first controldevice 23 causing that device to switch from the zero state to the onestate as soon as device 23 switches to the one state, it switches theswitches 21 and 22 to the one state also and so switch 21 opens andswitch 22 closes. When switch 21 opens, battery power to line 28 viaswitch 21 ceases, however, line 28 is still supplied battery power fromthe output of switch 24 through line 33 and so the second control device26 remains in the one state. Meanwhile, line 32 is now also energized bythe output of switch 22 and so the first control device 23 also remainsin the one state. Thus, we find with the ignition switch in theignition-start position, both of the control devices and all of theswitches in the starter control system are in the one state and thestarter motor is energized.

As soon as the engine starts and the voltage regulator 6 produces asufficient signal in line 11 to the second control device 26, thatdevice switches back to its zero state and so do switches 24 and 25 andso battery power to terminal IV ceases and the starter motor is nolonger energized. However, at this point the first control device 23 andswitches 21 and 22 remain in the one state and are held there becausebattery power from terminal II feeds through switch 22 to line .32 andholds the first control device 23 in the one state. Thereafter, shouldthe engine stop, it can not be restrained except by first de-energizingterminal II and this is done, of

course, by returning the ignition switch to the off posi-' tion. Thestarter motor can not be reenergized because so long as the firstcontrol device 23 is in the one state and the second control device 26is in the zero state, switches 21 and 24 are both open and so no batterypower is fed to terminal IV. Terminal IV can not again be energizeduntil the first control device 23 is also returned to its zero state andthis can occur only be deenergizing terminal II. Thus, the systemoutlined in FIG. 2, protects the starter motor and engine from attemptsby the operator to energize the starter motor after the engine hasstarted and prevents the operator from reenergizing the starter motorwithout first returning the ignition switch to the off position.

FIG. 3 shows an embodiment operating as described above with referenceto FIG. 2 including two solenoids 34 and 35 which function as the firstand second control devices, respectively and mechanically drive the twoposition switches 21 to 25. This system includes a diode 29 and a diode36, oriented as shown when the positive terminal of the battery isgrounded. In this case, a diode 29 prevents current flow in line 28 fromterminal IV and so the current flow from terminal IV must be throughline 27, switch 24 and from switch 24 to terminal III. Thus,substantially the complete starter control system is formed by two pairsof switches controlled by two solenoids. The system in FIG. 3 respondsto a signal in terminal V from the engine voltage regulator which is fedto solenoid coil 35 via a diode 36 electrically directed as shown forsuch a system when the positive terminal of the battery is grounded. Inthis same system, if the negative terminal of the battery is grounded,then the direction of the diode 36 is reversed.

Another embodiment of the starter control system also using two pairs ofswitches controlled by two solenoids is illustrated in FIG. 4 anddiffers slightly from the system in FIG. 2. In this embodiment, inaddition, an

impedence 38 is provided in series with diode 36. DC

output from an alternator feeds through diode 39 making the DC potentialon coil 35 zero causing said coil to de-energize so that switches 24 and25 return to their zero position.

The embodiments illustrated in FIGS. 5 and 6 are identical except thatin FIG. 5 the positive terminal of the battery is grounded and in FIG. 6the negative terminal of the battery is grounded. This system includesan SCR in place of switch 22. Otherwise, the switches and solenoids inthe system shown in FIGS. 5 and 6 are the same as shown in FIGS. 2 and 3and so they have the same reference numbers. The SCR is shown in FIG. 5(battery positive terminal grounded), is denoted 42. When this SCR drawscurrent to terminal II, solenoid coil 34 is energized. Furthermore, thisSCR can not draw current until line 32 is grounded via switch 25 (whenswitch 25 is closed) to terminal I. Thus, the SCR 42 is effective in thesame fashion as switch 22 in FIGS. 2 and 3.

In operation, when the ignition switch 15 switched from the off to theIgnition position, terminal II is energized. At this point in time,switch 21 is closed, switches 24 and 25 are open and neither of thesolenoid coils 34 or 35 are energized. Next, when the ignition switch isswitched from ignition to ignition-start, terminal III is energized,battery power is fed through switch 21 to terminal IV and current isdrawn from terminal V through diode 36, solenoid coil 35, line 28 andswitch 21 to terminal III, energizing solenoid 35 which switchesswitches 24 and 25 from their zero state to their one state and so theseswitches close. When switch 25 closes, it applies ground from terminal Ito line 32 connected to the SCR 42. At the same time, switch 24 whichalso closes draws current through solenoid 35. When the SCR is groundedas described, it draws current through solenoid 34 from terminal I toterminal II and so the solenoid 34 is energized and it actuates switch21 opening that switch. When switch 21 opens, it no longer connectsterminals III and IV and no longer draws current through solenoid 35,however, switch 24 continues to draw current through solenoid 35 untilthe engine starts and produces a sufficient signal at terminal V to stopcurrent flow through diode 35 to solenoid 35 and so this solenoid isde-energized and the switches 24 and 25 return to their open positionand battery power is no longer fed from terminal III through switch 24to terminal IV and so the engine start motor is de-energized. However,the SCR 42 continues to conduct even through it is not grounded throughline 32, and so long as it conducts, it draws current through solenoid34 which holds switch 21 open. Thus, with switch 21 open and switch 24open, there can be no voltage applied to terminal Iv from terminal III.When this condition occurs, the ignition switch must be returned to theoff position removing battery voltage from terminal II so that the SCRceases to conduct, solenoid 34 is de-energized and switch 21 closes.Thus, it is seen, that the circuit in FIG. 5 stops electric power to theengine start motor as soon as the engine starts and exceeds the crankingspeed and the circuit also prevents reenergizing the starter motorfollowing an attempt to start the engine except by first returning theignition switch to the off position.

A very similar system in FIG. 5 is shown in FIG. 6, the only differencebeing that the negative terminal of the battery is connected to groundand so the direction of the diode 36 is reversed and the direction ofthe SCR 42 is reversed.

The various embodiments of the present invention described hereinprovide a starter control system in circuit between the engine ignitionswitch and starter motor solenoid switch. Some of the embodimentsdescribed herein include conventional solenoid actuated ganged switchesand the last embodiment includes an SCR functioning as a switch.Clearly, all these switches and the solenoid controls could be solidstate devices or more particularly, binary circuits functioninggenerally as described herein with respect to FIG. 2. Clearly, these andother components could be substituted for the components describedwithout departing from the spirit and scope of the invention as setforth in the appended claims.

What is claimed is: 1. In an engine start system for starting an engineand energizing the ignition thereof, said systeru including a startermotor, a source of electrical energy, an electrically controlled startmotor switch, having an electrical input control, said switchelectrically connecting the source to the motor and an ignition switchelectrically connecting the source to the starter motor switch inputcontrol and to the engine ignition, said ignition switch having OFF,IGNITION and IGNITION-START positions producing in the latter twopositions an ignition output signal and an ignition-start output signal,respectively, means for controlling the sequence of energization of thestarter motor comprising,

electrical switches A 8,, A and B each having an electrical signal inputand output and a control input and each capable of being in a conductingor a non-conducting state between the signal input and output thereof,first electrically energized control means for switches A and B havingan electrical input and having an output and capable of being in one orthe other of two electrical states represented by the output thereof,second electrically energized control means for switches A and B havingan electrical input and having an output and capable of being in one orthe other of two electrical states represented by the output thereof,first means coupling the output of the first control means to thecontrol inputs of switches A and B second means coupling the output ofthe second control means to the control inputs of switches A and E2:

the said ignition output signal being coupled to the signal inputs ofswitches B and B the ignition-start output signal being coupled to thesignal inputs of switches A and A means connecting the outputs ofswitches B and B to the first control means input and means connectingthe outputs of switches A, and A to the second control means input andto the starter motor electrical input control,

whereby the starter motor switch cannot be energized to electricallyconnect the source to the starter motor following switching the ignitionswitch from the IGNITION-START position to the IGNITION position, exceptby first switching the ignition switch to the OFF position.

2. An engine start system as in claim 1 wherein,

the first control means and switches A and B are provided by a solenoidrelay having two switches driven by the solenoid.

3. An engine start system as in claim 2 wherein,

the second control means and switches A and B are provided by a solenoidrelay having two switches wherein the solenoid drives both switches.

4. An engine start system as in claim 1 wherein, one

or more of the switches is a semi-conductor device.

5. An engine start system as in claim I wherein,

the electrical state of the second electrically energized control meansis changed from one state to another state by the output of switch A andthereafter compelled to remain in said other state by the output ofswitch A when the ignition switch is in the IGNITION-START position,

the electrical state of the first electrically energized control meansis changed from one state to another state by the output of switch Bwhen the ignition switch is in the IGNITION-START position andthereafter compelled to remain in said other state by the output ofswitch B when the ignition switch is in the IGNITION position,

electrical energy to the starter motor switch electrical input controlis provided through switch A when the ignition switch is in theIGNITION- START position and the first control means is not in saidother state,

electrical energy to the starter motor switch electrical input controlis provided through switch A when the ignition switch is in theIGNITION- START position and the second control means is in said otherstate, and

switch B holds the first control means when the ignition switch is inthe IGNITION position.

6. An engine start system as in claim 1 wherein,

the first and second electrically energized control means and theswitches A B A and B each has two states, a zero state and a one stateand all switches and the first and second control means are energized bythe source through the ignition switch and are in the zero state whenthe ignition switch is in the OFF position.

7. An engine start system as in claim 6 wherein,

a signal is produced by the engine representative of the engine speedand said engine speed signal is applied to the input of the secondcontrol means changing the state thereof.

8. An engine start system as in claim 6 wherein,

the zero state of the first and second control means occurs when theyare not electrically energized.

9. An engine start system as in claim 8 wherein,

the starter motor switch is initially energized while the first andsecond control means are in the zero state.

10. An engine start system as in claim 9 wherein,

a signal is produced by the engine representative of the engine speedand said engine speed signal is applied to the input of the secondcontrol means com pelling said last mentioned means to remain in thezero state.

11. An engine start system as in claim 10 wherein, the engine speedsignal from the engine is initiated from an engine generator driven bythe engine. 12. An engine start system as in' claim 10 wherein, theengine speed signal from the engine is applied through a diode.

13. An engine start system as in claim 12 wherein,

, the outputs of switches A and A are connected by A and can be providedthrough switch A 3,885,543 May 27, 1975 Patent No. Dated Inventor) MarkSwartz It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Column 1, line 19 after "which" insert time Column 1 line 23, after"which" insert time Column 1, lines 45 and 46 delete "be severelydamaged" and insert cause severe damage to the engine flywheel and/ orstarter motor Q Column 1, line 52, delete "is" and insert" and engineflywheel are Column 1, line 53, after "been" insert made Column 4, line59, delete "27" and insert 33 Column 5, line 20, delete "restrained" andinsert restarted Column 5, line 29, delete "be" and insert by Signed andSealed this vlsEALl ninth Day of December 1975 A ttest:

RUTH C. MASON Commissioner ofParenrs and Trademarks FORM P0-10SOHO-6USCOMM-DC some-P69 U,S. GOVERNMENT PRINTING OFFlCE. 869- 9 UNITED STATESPATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 885 D t d y 27 975lnventofls) Mark Swartz It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 1, line 19, after "which" insert time Column 1, line 23, after"which" insert time Column 1, lines 45 and 46, delete "be severelydamaged" and insert cause severe damage to the engine flywheel and/Column 1, line 52, delete ."is" and insert--- and engine flywheel areColumn 1, line 53, after "been" insert made 8 Column 4, line 59, delete"27" and insert 33 Column 5, line 20, delete "restrained" and insertrestarted Column 5, line 29, delete "be" and insert Sugncd and Emalcdthis ninth a O {SEAL} D f December1975 Arrest:

RUTH- C. MA.SON C. MARSHALL DANN A fts mg ffic Commissioner oflarems andTrademarks FORM PO 1 H USCOMM-DC 60376-P69 U75. GOVERNMENT PRINTINGOFFICE, 930

1. In an engine start system for starting an engine and energizing theignition thereof, said system including a starter motor, a source ofelectrical energy, an electrically controlled start motor switch, havingan electrical input control, said switch electrically connecting thesource to the motor and an ignition switch electrically connecting thesource to the starter motor switch input control and to the engineignition, said ignition switch having OFF, IGNITION and IGNITION-STARTpositions producing in the latter two positions an ignition outputsignal and an ignition-start output signal, respectively, means forcontrolling the sequence of energization of the starter motorcomprising, electrical switches A1, B1, A2 and B2 each having anelectrical signal input and output and a control input and each capableof being in a conducting or a non-conducting state between the signalinput and output thereof, first electrically energized control means forswitches A1 and B1 having an electrical input and having an output andcapable of being in one or the other of two electrical statesrepresented by the output thereof, second electrically energized controlmeans for switches A2 anD B2 having an electrical input and having anoutput and capable of being in one or the other of two electrical statesrepresented by the output thereof, first means coupling the output ofthe first control means to the control inputs of switches A1 and B1second means coupling the output of the second control means to thecontrol inputs of switches A2 and B2, the said ignition output signalbeing coupled to the signal inputs of switches B1 and B2 theignition-start output signal being coupled to the signal inputs ofswitches A1 and A2, means connecting the outputs of switches B1 and B2to the first control means input and means connecting the outputs ofswitches A1 and A2 to the second control means input and to the startermotor electrical input control, whereby the starter motor switch cannotbe energized to electrically connect the source to the starter motorfollowing switching the ignition switch from the IGNITION-START positionto the IGNITION position, except by first switching the ignition switchto the OFF position.
 2. An engine start system as in claim 1 wherein,the first control means and switches A1 and B1 are provided by asolenoid relay having two switches driven by the solenoid.
 3. An enginestart system as in claim 2 wherein, the second control means andswitches A2 and B2 are provided by a solenoid relay having two switcheswherein the solenoid drives both switches.
 4. An engine start system asin claim 1 wherein, one or more of the switches is a semi-conductordevice.
 5. An engine start system as in claim 1 wherein, the electricalstate of the second electrically energized control means is changed fromone state to another state by the output of switch A1 and thereaftercompelled to remain in said other state by the output of switch A2 whenthe ignition switch is in the IGNITION-START position, the electricalstate of the first electrically energized control means is changed fromone state to another state by the output of switch B2 when the ignitionswitch is in the IGNITION-START position and thereafter compelled toremain in said other state by the output of switch B1 when the ignitionswitch is in the IGNITION position, electrical energy to the startermotor switch electrical input control is provided through switch A1 whenthe ignition switch is in the IGNITION-START position and the firstcontrol means is not in said other state, electrical energy to thestarter motor switch electrical input control is provided through switchA2 when the ignition switch is in the IGNITION-START position and thesecond control means is in said other state, and switch B2 holds thefirst control means when the ignition switch is in the IGNITIONposition.
 6. An engine start system as in claim 1 wherein, the first andsecond electrically energized control means and the switches A1, B1, A2and B2 each has two states, a zero state and a one state and allswitches and the first and second control means are energized by thesource through the ignition switch and are in the zero state when theignition switch is in the OFF position.
 7. An engine start system as inclaim 6 wherein, a signal is produced by the engine representative ofthe engine speed and said engine speed signal is applied to the input ofthe second control means changing the state thereof.
 8. An engine startsystem as in claim 6 wherein, the zero state of the first and secondcontrol means occurs when they are not electrically energized.
 9. Anengine start system as in claim 8 wherein, the starter motor switch isinitially energized while the first and second control means are in thezero state.
 10. An engine start sysTem as in claim 9 wherein, a signalis produced by the engine representative of the engine speed and saidengine speed signal is applied to the input of the second control meanscompelling said last mentioned means to remain in the zero state.
 11. Anengine start system as in claim 10 wherein, the engine speed signal fromthe engine is initiated from an engine generator driven by the engine.12. An engine start system as in claim 10 wherein, the engine speedsignal from the engine is applied through a diode.
 13. An engine startsystem as in claim 12 wherein, the outputs of switches A1 and A2 areconnected by a diode, whereby electrical energy to the starter motorswitch cannot be provided through a switch A1 and can be providedthrough switch A2.